The present invention relates to a device for sampling and dispensing adjustable volumes of liquid samples, with numerical display.
In general, the invention therefore applies both to micro-pipettes equipped at their lower end with sampling cones or to positive-displacement pipettes and to all other sampling and dispensing devices such as, for example, diluting devices.
Devices of this type, of the prior art, have the disadvantage of comprising housings of too great a length. This excessive axial dimension of the housings is necessitated by the very design of the adjusting and display mechanisms according to the prior art, for example illustrated by French Pat. No. 2203680, also U.S. Pat. No. 3,827,305. It should be noted that such a disadvantage becomes particularly annoying in the handling of so-called "positive-displacement" pipettes, that is to say those having, in addition, in their lower part a calibrated capillary tube of a certain length in which a tight-fitting piston moves.
In general, it would clearly be more convenient to have available such dispensing and sampling instruments having a shorter length. This would make it possible, in fact, either to handle them better in the laboratory or to accommodate them more easily within more sophisticated appliances such as automatic diluting devices.
The object of the present invention is therefore completely to modify the design of such adjusting and display mechanisms, so as to enable their axial dimensions to be limited.